The primary goal of the Pathology Core (PC) is to provide investigators of this program project with a centralized, comprehensive facility for human tissue-based research. The resource will enhance the infrastructure, optimize tissue use and facilitate rapid advances in specific projects by 1) providing appropriate human tissues and associated data in an equitable and ethical manner, 2) providing professional expertise in histo- and molecular pathology, and 3) performing tissue based experimentation. The PC also implements stringent quality control standards to ensure that consistent, valid services are provided to investigators using the shared resource. This centralized core is the most efficient and cost-effective means to provide these necessary research components to multiple investigators in this program by eliminating duplication of effort and equipment, and centralizing quality control. The resource will also be a logistic, technological and intellectual bridge between basic and clinical investigators. The specific aims of the core are: 1) To provide pathology expertise at all stages of project development and experimentation using human tissue. 2) To procure well-characterized neoplastic and nonneoplastic human tissue required for individual projects without compromise of patient care. 3) To record and maintain pertinent histopathology data in a secure, relational database designed for efficient data transfer and analyses of clinical, genetic and molecular correlations. 4) To consistently process, store and distribute tissue samples and biomaterials according to individual research of investigators of this program project. 5) To provide routine histologic techniques, microdissection for tissue component purification, and technical assistance in tissue-based experimentation. 6) To provide immunohistochemistry services including antibody characterization and optimization for immunohistochemistry.